Does anyone know what the non reclosure voltage of a standard fs 4 starter is?

I know a standard tulamp ballast has a ocv of around 240v and the f40t12 lamp is around 105v.
I would think the voltage is above 135v because 240-105=135v.

Also what happens when you use a starter with a high reclosure voltage?
Say for example a Philips S16.
http://download.p4c.philips.com/lfb/f/fp-928390930371
It says it has a non reclosure voltage of 170v but an operating voltage of 220v.

How would these react on a usa tulamp ballast with f40t12 lamps?

I'm guessing the non reclosure voltage is between 150 and 200 V as the ballast OCV is over 200V. When the lamp is cold, the starter sees ballast OCV and closes, but when operating, the voltage of the lamp "robs" part of the voltage seen by the starter, and lowers the potential between contacts below the threshold so the starter does not close. A European starter such as the Philips S16 you mention would behave in a similar fashion as the American FS-4. The only difference is the lack of an autotransformer ballast in Europe as the mains voltage is sufficient to light moderately long lamps.

As for the standard N. American tulamp ballasts, those are autotransformers and supply an OCV of at least 200 volts to both lamps, so FS-4 starters will close. FS-2 starters, either on tulamp or single lamp 40W ballasts, will not stay open as the voltage is above their threshold of about 90ish volts.

I would guess the reclosure (aka trigger) voltage is around 180..240V peak (the rme does not matter, mainly with non-sinusoidal shapes).
200V ballast OCV means about 280V peak, sufficiently (you always need some margin) above the 240V upper limit guess I made.
But a 105Varc lamp does mean 105V arc voltage, but on top of that are "reignition spikes" - voltage overshoots each time the current passes zero and so the arc extinguishes and has to reignite again for the next half cycle. These peaks tend to be few 10's of V (example here), so I would guess below 150V for a nominally 105V arc lamp.
And these reignition spikes then should not trigger the starter, so the starter trigger voltage has to be then above the 150V, therefore (some margin again) the 180V as my minimum limit guess.

And as any other device, the starter triggering voltage will exhibit some tolerance, I would expect about +/-10..15% to be about the ball park, so there is not much room out of the guesses I made...

Actually i think this is not allways met - Its not uncommon to see S10 slightly glowing (not enough to close) continuously with a working intact 36W tube

I don't particularly fancy a glowing starter once the lamp has struck. Seems to me it could overheat, but since you mention it is not uncommon, I guess it won't. Does it shorten the life of the starter ? I've had it happen once but it was a lamp/ballast mismatch (sort of an experiment).

Actually i think this is not allways met - Its not uncommon to see S10 slightly glowing (not enough to close) continuously with a working intact 36W tube

The glowing starter does not automatically mean an arc voltage above the triggering one. But it does mean the reignition overshoot is pretty close.

Otherwise the only effect of low current glow is blackening of the starter bulb. Because it is not used as a light source, it usually does not matter at all.

However when the fluorescents age, the starter may get warmer and that does start to degrade the starter, mainly when the lamp really approaches EOL. This is the reason, why you should always replace the starter with the lamp - the dying lamp has just damaged it. Mainly the capacitor is the thing going bad due to the long term heat exposure...
The cut-out starters are way better in this - when they get hotter, the bimetal trips and disconnects the starter. But it has its drawback: This cut out tripping uses to happen just before the lamp really dies completely, so it still somehow works (although it is EOL). The consequence is the tendency of the maintenance to just reset the starter in an attempt to "not waste money on replacing working tubes" (and then claiming "these cutouts trigger without any reason after very short time")

Alright thanks everyone. I'm going to try some European starters once i order them

Let me know what you order and where as I've been trying to find some with very little success.

I was planning to just order from eBay.

There are tons of different models.

OK, I'll have a look. Thanks.